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This wikipedia page contains a sentence:

A fifth 906V battery with 155 Ampere-hour capacity was added to support the increased energy consumption from the improved electronics.

906 V seems very high, 90.6 V is believable.

Is there any other information about Soyuz DC system voltage?

Machavity
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Uwe
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    906V would have its advantages - you could save some launch weight in high current wiring :) – rackandboneman Jul 16 '18 at 18:41
  • @rackandboneman: You would need less weight for the wiring conductors, but more weight for wiring isolation. But the reliability of so many battery cells in series to get 906 V would be too small. – Uwe Jul 16 '18 at 20:26
  • Very high voltage batteries of small capacity and low max current, built as stacks of thin metal foil and electrolyte soaked paper (voltaic cells), are reliable and lightweight enough, a good source of high voltage where such is needed. But 155Ah is a very respectable capacity and way more than I'd see in form of a voltaic pile. – SF. Jul 16 '18 at 21:50
  • Insulation is light, and most any plastic insulation can withstand 1000V if transient free and kept safe from damage. – rackandboneman Jul 17 '18 at 07:49

1 Answers1

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"Soyuz: A Universal Spacecraft" says the electrical system produces 23-34 volts. I saw a reference to a nominal 28VDC supply to the spacecraft in the Soyuz launcher manual; 28VDC is a global standard for aircraft power supplies.

I think "906V" is a part number, not a voltage; the source for that section of the WP page says (my bolding):

Finally, the spacecraft was upgraded with an extra (fifth) power-storage battery, known as 906V, with a capacity of 155 ampere-hour.

Russell Borogove
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